26 June 2018 - FACTS ABOUT THE AMAZING JELLYFISH

FACTS ABOUT

THE AMAZING JELLYFISH

G'day folks,

No doubt all of you have come across these creatures at some stage, but what are they? Jellyfish
or jellies are soft bodied, free-swimming aquatic animals with a gelatinous
umbrella-shaped bell and trailing tentacles. The bell can pulsate to acquire
propulsion and locomotion.

Jellyfish (also known as
jellies and sea jellies) are boneless animals
that float freely through the world's oceans.
Although jellyfish exist in our oceans
worldwide they are particularly prominent in coastal areas. Jellyfish can be
found in all shapes and sizes
from just a few inches in diameter to well over a metre.

There are thought to be
around 2,000 different species
of jellyfish, the most common being the big, colourful ones found in warmer
coastal areas. There are four different types
of jellyfish that are categorised by their shape and the way in which they
behave.

Despite the name, jellyfish
are not actually fish
but are instead classed in a group
of their own as they are unlike any other animal
on Earth. The body of the jellyfish is made up of a non-living jellylike
substance called mesoglea. This jelly is surrounded by a layer of skin that is
just one cell thick. The body of the jellyfish is mainly made up of water,
around 90% in fact.

Jellyfish also
have tentacles around their mouths that vary in length depending on the species
of jellyfish. The jellyfish use their tentacles to both catch and sting their prey.
The tentacles of the jellyfish are covered in a skin that contains special
cells, some that sting, some that grip and some that stick. The jellyfish is
able to produce these cells at an alarming rate so they are effectively
disposable to the jellyfish.

Some jellyfish
stings contain poison which the jellyfish uses to stun and kill its prey.
The box jellyfish, found in the oceans
around Australia,
has a sting powerful enough to be fatal to humans.
The long tentacles of the jellyfish are what produces the sting.

The jellyfish
is a carnivorous animal
and despite its appearance, the jellyfish is a remarkably efficient predator.
Jellyfish use their tentacles to stun their prey
before grabbing onto it and bringing it into their mouth. Jellyfish prey
on all kinds of aquatic animals
such as small fish,
eggs and invertebrates
along with anything else that gets stuck in their tentacles.

Due to the
fact that many species
of jellyfish are transparent, they are often hard for predators
to spot. However, jellyfish are drifters and move very slowly through the water
sometimes using their tentacles to propel them along. Jellyfish are eaten by humans,
sharks, squid
and occasionally birds.

Jellyfish release their eggs and sperm into the water
which eventually meet and the egg is fertilised. The jellyfish egg quickly
becomes and embryo
and begins to develop in it's water world.

Clancy's comment: Some are beautiful, but many like we have in Australia can be deadly.